#243F72
Closest named color: Twilight Blue (#0A437A). oklch(37.4% 0.094 261.9), rgb(36, 63, 114).
Aa
White text reads best on this color (10.34:1).
About this color
#243F72 is a dark, moderately saturated blue. In OKLCH its lightness is 37%, its chroma 0.094 and its hue 262°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.023 away. White text reads best on it, at 10.34:1.
| Hue family | Blues |
| Lightness | dark (37%) |
| Chroma | moderately saturated (0.094) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 2.02:1 |
| White text | 10.34:1 |
Values
| HEX | #243F72 |
| RGB | rgb(36, 63, 114) |
| HSL | hsl(219, 52%, 29%) |
| OKLCH | oklch(37.4% 0.094 261.9) |
Contrast
WCAG 2 contrast ratios are the conformance target: AA needs 4.5:1 for body text and 3:1 for large text, AAA needs 7:1. APCA Lc values are supplementary guidance from the WCAG 3 drafts.
| Pair | WCAG 2 | Result | APCA | APCA guidance |
|---|---|---|---|---|
| White text on #243F72 | 10.34:1 | AAA | Lc -97.8 | Preferred for body text |
| Black text on #243F72 | 2.02:1 | Fails | Lc 10.1 | Not readable |
| #243F72 text on white | 10.34:1 | AAA | Lc 93.8 | Preferred for body text |
| #243F72 text on black | 2.02:1 | Fails | Lc -8.7 | Not readable |
Tints and shades
A 50–950 scale built in OKLCH: the hue is held, lightness follows a Tailwind v4-like curve, and every step is kept inside the sRGB gamut. This color sits at step 900.
-
Step 50
50
#F2F6FC
oklch(97.2% 0.009 258.3)
-
Step 100
100
#E2EAF8
oklch(93.5% 0.021 261.8)
-
Step 200
200
#CBDAF4
oklch(88.5% 0.039 261.5)
-
Step 300
300
#A8C1EF
oklch(80.8% 0.071 262.5)
-
Step 400
400
#7AA0E7
oklch(70.7% 0.113 262.3)
-
Step 500
500
#5887E0
oklch(63.2% 0.144 262.1)
-
Step 600
600
#3D6FCD
oklch(55.6% 0.155 261.7)
-
Step 700
700
#2F5CB2
oklch(49.1% 0.146 261.8)
-
Step 800
800
#284C90
oklch(42.8% 0.12 261.7)
-
Step 900
900 (this color)
#243F72
oklch(37.4% 0.094 261.9)
-
Step 950
950
#162643
oklch(27.1% 0.058 261.5)
#243F72 with color blindness
Simulated with the Machado et al. (2009) model. ΔE is how far the color moves: below about 0.02 you would not notice a change.
| Vision | Seen as | Shift (ΔE) |
|---|---|---|
| Protanopia (no red cones) | #274474 | 0.016 |
| Deuteranopia (no green cones) | #1B3D71 | 0.012 |
| Tritanopia (no blue cones) | #004B53 | 0.077 |
| Achromatopsia (no color) | #404040 | 0.094 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #243F72
#243F72
oklch(37.4% 0.094 261.9)
- #553C00
#553C00
oklch(37.4% 0.077 82.1)
Analogous
Neighbouring hues, 30° either side.
Split complementary
The two hues beside the complement (150° and 210°).
Triadic
Three hues spaced 120° apart.
Palettes with this color
Curated palettes that contain a color within ΔE 0.04 (OKLab) of #243F72, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.023
- Marine Blue #01386A ΔE 0.039
- Dark Grey Blue #29465B ΔE 0.050
- Cobalt #1E488F ΔE 0.052
- Light Navy #155084 ΔE 0.054
- Prussian Blue #1D3557 ΔE 0.054
- Deep Sea Blue #015482 ΔE 0.063
- Charcoal #264653 ΔE 0.063
Use #243F72 in your product
Turn it into light and dark UI roles checked for contrast, then export to Tailwind v4, shadcn/ui, CSS or design tokens.